html, body {
    height: 100%;
    display: flex;
    flex-direction: column;
  }

/* Set a soft green background for the entire page */
body {
    font-family: 'Segoe UI', sans-serif;
    background-color: #e6f2e1; /* soft green */
    color: #2e2e2e; /* dark gray text */
    text-align: center;
    margin: 0;
    padding: 20px;
  }
  
  /* Title style */
  h1 {
    font-family: 'Poppins', sans-serif;
    font-size: 3rem;
    color: #1a472a;
    margin-bottom: 10px;
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.1);
    animation: fadeIn 1s ease-in;
  }
  
  
  /* Section for input fields and add button */
  #input-section {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin: 30px auto 0 auto;
    max-width: 800px; /* match flashcard width */
    flex-wrap: wrap; /* lets it wrap on smaller screens */
  }
  
  
  #input-section input {
    padding: 14px;
    margin: 5px;
    width: 300px;
    font-size: 1rem;
    border: 1px solid #999;
    border-radius: 8px;
  }
  
  #add-card-btn {
    padding: 14px 28px;
    font-size: 1rem;
    background-color: #4e944f;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
  }
  
  
  #add-card-btn:hover {
    background-color: #3b773e; /* darker green on hover */
  }
  
  #flashcard-container {
    perspective: 1000px;
    margin: 60px auto 30px;
    width: 400px;        
    height: 260px;       
    display: flex;
    justify-content: center;
    align-items: center;
  }
  /* Flashcard styling */
  .card {
    width: 100%;
    height: 100%;
    position: relative;
    transition: transform 0.6s;
    transform-style: preserve-3d;
    cursor: pointer;
  }
  
  /* Flipped state */
  .card.flipped {
    transform: rotateY(180deg);
  }
  
  /* Front and back of the card */
  .front,
  .back {
    background-color: #fdf6e3; /* soft brown/earthy cream */
    color: black;
    border: 2px solid #1a472a; /* dark green border */
    border-radius: 12px;
    padding: 20px;
    position: absolute;
    width: 100%;
    height: 100%;
    font-size: 1.1rem;
    backface-visibility: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  
  /* Back of the card flipped */
  .back {
    transform: rotateY(180deg);
  }
  
  
  #navigation button {
    padding: 10px 20px;
    margin: 0 10px;
    background-color: #2e2e2e; /* black/dark */
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
  }
  
  #navigation button:hover {
    background-color: #444;
  }
  /* Modal background overlay */
#welcome-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 50, 0, 0.7); /* dark greenish overlay */
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 999; /* stay on top */
  }
  
  /* Modal box content */
  .modal-content {
    background-color: #fdf6e3; /* soft earthy cream */
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    max-width: 500px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  }
  
  .modal-content h2 {
    color: #1a472a; /* deep green */
    margin-bottom: 10px;
  }
  
  .modal-content p {
    color: #333;
    font-size: 1rem;
    margin-bottom: 20px;
  }
  
  /* "Let's Get Started" button */
  #start-btn {
    padding: 10px 20px;
    background-color: #4e944f; /* green */
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
  }
  
  #start-btn:hover {
    background-color: #3b773e; /* darker hover */
  }
  /* Fun Fact / Study Tip Section */
  #study-fact-container {
    text-align: center;
    margin-top: 50px;
    padding: 10px;
    width: 100%;
  }
  
  #study-fact-wrapper {
    display: inline-block;
    position: relative;
    font-size: 1.1rem;
    color: #2e2e2e;
    font-style: italic;
    opacity: 1;
    transition: opacity 2s ease-in-out;
  }
  
  #study-fact-wrapper.fade-out {
    opacity: 0;
  }
  
  #info-icon {
    margin-left: 6px;
    cursor: pointer;
    color: #4e944f;
    font-size: 1rem;
    vertical-align: middle;
    user-select: none;
  }
    
  
  #manage-buttons button {
    padding: 8px 16px;
    margin: 0 8px;
    background-color: #1a472a;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
    transition: background-color 0.3s;
  }
  
  #manage-buttons button:hover {
    background-color: #336633;
  }
  /* Flex layout: Nav | Flashcard | Manage */
  #card-section {
    display: grid;
    grid-template-columns: 1fr 480px 1fr;
    align-items: center;
    justify-content: center;
    gap: 40px;
    margin: 30px auto;
    max-width: 1000px; /* Optional: allows more breathing room */
  }
  
  
  /* Navigation & Manage buttons stacked horizontally */
  #nav-buttons,
  #manage-buttons {
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: center; /* center buttons horizontally */
  }


  
  #nav-buttons button,
#manage-buttons button {
  width: 100%;
  padding: 18px; /* increased from 14px */
  font-size: 1.1rem; /* slightly larger text */
  background-color: #2e2e2e;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-weight: bold;
}
  #nav-buttons button:hover,
  #manage-buttons button:hover {
    background-color: #444;
  }
  

  /* Floating History Button */
#history-toggle {
    position: fixed;
    bottom: 20px;
    right: 20px;
    padding: 12px 20px;
    background-color: #4e944f;
    color: white;
    border: none;
    border-radius: 30px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    cursor: pointer;
    font-weight: bold;
    z-index: 1000;
    transition: background-color 0.3s;
  }
  
  #history-toggle:hover {
    background-color: #3b773e;
  }
  
  /* Slide-in History Panel */
  #history-panel {
    position: fixed;
    top: 0;
    right: -400px;
    width: 350px;
    height: 100%;
    background-color: #fdf6e3;
    box-shadow: -4px 0 12px rgba(0, 0, 0, 0.2);
    transition: right 0.4s ease-in-out;
    z-index: 999;
    padding: 20px;
    overflow-y: auto;
  }
  
  #history-panel.open {
    right: 0;
  }
  
  #history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
  }
  
  #close-history {
    background: none;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
  }
  
  #history-list {
    list-style-type: none;
    padding-left: 0;
    font-size: 0.95rem;
  }
  
  #history-list li {
    margin-bottom: 12px;
    padding: 10px;
    border-bottom: 1px solid #ddd;
  }

 
  /* Edit Modal Styling */
.modal {
    display: none;
    position: fixed;
    z-index: 1001;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 50, 0, 0.6);
  }
  
  .modal-content {
    background-color: #fdf6e3;
    margin: 10% auto;
    padding: 20px;
    border: 2px solid #1a472a;
    border-radius: 12px;
    width: 90%;
    max-width: 400px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    animation: slideIn 0.4s ease-in-out;
  }
  
  @keyframes slideIn {
    from {
      transform: translateY(-20px);
      opacity: 0;
    }
    to {
      transform: translateY(0);
      opacity: 1;
    }
  }
  
  .modal-content input {
    width: 90%;
    padding: 10px;
    margin: 10px 0;
    border-radius: 8px;
    border: 1px solid #ccc;
  }
  
  .modal-buttons {
    display: flex;
    justify-content: center;
    gap: 10px;
  }
  
  .modal-buttons button {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-weight: bold;
    cursor: pointer;
    background-color: #4e944f;
    color: white;
  }
  
  .modal-buttons button:hover {
    background-color: #3b773e;
  }
  .modal-content label {
    display: block;
    text-align: left;
    margin-top: 10px;
    margin-bottom: 5px;
    color: #1a472a;
    font-weight: bold;
    font-size: 0.95rem;
  }
  #site-footer {
    margin-top: auto;
    font-size: 1rem;
    color: #2e2e2e;
    text-align: center;
    padding: 20px 0;
  }
  .card, .front, .back {
    box-sizing: border-box;
  }
  #undo-btn {
    background-color: #2d6a4f; /* soft green */
  }
  #undo-btn:hover {
    background-color: #22543d; /* darker on hover */
  }
  .undo-wrapper {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  
  .undo-label {
    position: absolute;
    bottom: -28px;
    background-color: #fdf6e3;
    color: #1a472a;
    font-size: 0.8rem;
    padding: 4px 8px;
    border-radius: 6px;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
    opacity: 0;
    pointer-events: none;
    white-space: nowrap;
    transition: opacity 0.1s ease-in-out;
    z-index: 10;
  }
  
  .undo-wrapper:hover .undo-label {
    opacity: 1;
  }
  .undo-wrapper button {
    width: 100%;
  }
  .undo-wrapper {
    width: 100%;
  }
  #tooltip-wrapper {
    display: inline-block;
    position: relative;
  }
  
  #tooltip {
    display: none;
    position: absolute;
    top: 120%;
    left: 50%;
    transform: translateX(-50%);
    background-color: #fdf6e3;
    border: 1px solid #4e944f;
    color: #2e2e2e;
    font-size: 0.9rem;
    padding: 8px;
    border-radius: 6px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    z-index: 1;
    text-align: center;
  }
  
  #tooltip a {
    color: #1a472a;
    text-decoration: underline;
  }
  
  #tooltip-wrapper:hover #tooltip {
    display: block;
  }
  
  @keyframes fadeIn {
    from {
      opacity: 0;
      transform: translateY(-10px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
  /* 📱 Mobile Responsiveness */
@media (max-width: 768px) {
    #card-section {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 20px;
    }
  
    #nav-buttons,
    #manage-buttons {
      flex-direction: row;
      flex-wrap: wrap;
      justify-content: center;
      gap: 10px;
    }
  
    #nav-buttons button,
    #manage-buttons button {
      width: 120px;
    }
  
    #flashcard-container {
      width: 90%;
      height: 240px;
    }
  
    #input-section {
      flex-direction: column;
      align-items: center;
    }
  
    #input-section input {
      width: 90%;
    }
  
    #add-card-btn {
      width: 90%;
    }
  
    #study-fact-wrapper {
      text-align: center;
      padding: 10px;
    }
  }